


Lying is such a toothache

by RedxBluechildren



Category: Undertale (Video Game)
Genre: Alternate Universe - Underfell, Blood and Injury, Other, Protective Papyrus, Protective Sans, Underfell Papyrus, Underfell Sans, Underfell W. D. Gaster
Language: English
Status: Completed
Published: 2017-05-16
Updated: 2017-05-16
Packaged: 2018-11-01 14:38:19
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence
Chapters: 1
Words: 2,103
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10923882
Author URL: https://archiveofourown.org/users/RedxBluechildren/pseuds/RedxBluechildren
Summary: Sans hasn’t always been the best big brother but that was for Papyrus own good but he slips up and back talks Gaster. Now he must be punished for lying and for protecting his younger brother, Or the Story of why Sans need’s the golden fake tooth.





	Lying is such a toothache

**Author's Note:**

> This is my second story here again sorry if there are any mistakes it's another Underfell au hope you like it! Again please leave a comment if you have some advice I'm trying to up lode a story almost every Tuesday also send prompts if you want.

Sans was going over doctor Gasters notes as his younger brother was staring at him from across the room. Sans didn’t look at him until Papyrus looked away to look at a monster that came in the lab the older of the two looked at the wound that was somewhat healing on the younger monsters face. It would most likely leave a scar he looked back at the notes when the other looked back at him he knew that Papyrus was still confused why Sans did that to him.

Sans wasn’t too proud of the action himself but it was the only way to show his brother how things worked down here. You don’t get to be to ‘NICE’ it gets you killed he couldn’t let Gaster kill Papyrus. Sans sighs knowing that even if he didn’t necessarily show that he cared about his little brother he might some day and it’ll be the death of him.

He rubbed his face tired from doing nothing but experiments with the Doctor also lack sleep since he started to dream of Papyrus screaming like he did when he hurt him. No sleeping wasn’t an option at the moment or more that he didn’t want to have that dream again plus getting punished by Gaster wasn’t a good thing either.

Sans looked up when he heard something drop and break he looked over at the Monster by Papyrus as it tries to clean up the broken glass Sans putting down the notes walked over to the monster.

“ **Look at this fucking mess.**.” He mutters more to himself then to the monster who froze a little the monster wasn’t really scared of Sans. Or maybe he was hell if he knew most monsters didn’t talk to him or even looked at him. But what he know is that the fear was most likely because this was **GASTERS** lab and Gaster get’s pissed at anyone who touches his things.

Sans could hear the monster basically piss their pants it was funny to see them squirm and he chuckled a little. “ **Look no sweat just get the fuck outta here before I call The doctor okay**?” The monster muttered a thank you and rushed out of the room the skeleton sighs out of annoyance because this was just more work for him.

He heard the glass being cleaned up and looked at his brother sometimes the kid was a mystery he was less happy go lucky after Sans had his little ‘lesson’ but he could still see that happy kid. That worried the older skeleton and would have to worry about it later he couldn’t let it show it’d give hope to Papyrus that his brother wasn’t heartless and go back to square one in this plan of his.

The door slams open both looks over it was W.D. Gaster and he didn’t look happy he glared at Papyrus and the mess that was on the floor. “ _ **What is that**_?” The elder monster growled and storms over to them pulling Papyrus up by his collar. “ _ **YOU Worthless bag of bones**_!!” Papyrus closed his sockets getting ready to get hit or worse.

  
“ **No Gaster it wasn’t his fault it was mine**.” Sans wasn’t thinking when he opens his mouth he did regret it but if Gaster hurt Papyrus the younger skeleton would just get used to being beaten up and his experiment would be worthless. Gaster looked at Sans letting go of Papyrus and walking closer to Sans having a dark look in his eyes Papyrus looked confused.

“ _ **Sans think nice and long about this my dear boy**_.” The doctor said in a dark voice to go along with his murderous glare. “ _ **Can you tell me WHO broke that vile**_?” Sans would gulp if he had a throat he started to sweat a little but didn’t back down from the scientist

 

“ **I told you I broke it and made Papyrus clean it up you know how lazy I am**.” He shrugs it off like he wasn’t freaking out he didn’t look at his younger brother or look away from Gaster who at first had a blank stare trying to figure out something then he had a sadistic smile.

He grabbed Sans by his shirt and picked him up ignoring Sans struggling and protest he looked at Papyrus. “ _ **It’s time to teach you both a new lesson about lying to me**_.” He said in a kind voice that Papyrus use to hearing Gaster told Papyrus to follow him as he was walking out of the current room other Monsters looked at them as they walked. Sans could hear them walking behind them he knew what was going to happen wouldn't be, or fun for him or Papyrus.

He took both of the brothers into a room with a table he forced Sans lab coat and shirt off throwing it behind him then strapped Sans into the table the smaller skeleton struggles with the restraints and looked at Gaster confused and somewhat scared. His head was strapped in last looking at the roof was his only option Sans knew this room it was the room where Gaster took the humans who fell down here and dissected or tortured them to learn more and that the mirror was a two-way mirror.

He was sure that there were some monsters behind it watching waiting to see what was going to happen nothing exciting has happened in the last few months a human hasn't fallen down and they haven't been any closer at breaking the barrier.

  
“ _ **Now now don’t worry my dear Sans everything will be forgiven after your punishment**_.” He looked at the younger brother after he pet his assistant head. “ _ **Papyrus go to that corner you are not to move from that spot but face so you can see Sans**_ ,” Gaster said as he started to hook things up to the smaller Skeleton monster he didn't want his assistant to die.

  
Papyrus did as he was told standing in the corner but face the table so he could see Sans the ‘good’ doctor walked over to the counter and took a pair of pliers from the table. The older monster walked over to put on his gloves he put them on and looked at Sans with a hint of excitement gleaned in his eyes he walked over to the table with the pliers in hand. Sans was breaking out in his mind he wasn't strong he has 1 Hp the doctor wouldn't do anything too bad that would kill him right? He wouldn't be able to help his brother and what would happen to Papyrus?!

 

“ ** _Now I need you to open your mouth Don't worry you're not going to die you'd be no use to me dead_**.” Gaster told Sans the shorter skeleton did as he was told worried about what he was going to do. “ _ **Good now don’t hold back on any screaming we have an audience and I want to know you are understanding and learning your lesson Sans**_.” The pliers were tapped on a couple of his teeth Sans could feel his soul beating fast from the fear he was now feeling.

Gaster continues to tap each tooth until he reaches the fourth tooth on Sans’s top teeth he open the pliers and looked at Papyrus as he took hold of the tooth. He could see the panic in the young monsters eyes and he smirked looking back at his assistant seeing the fear in his eyes gave him much joy.

The doctor could smell the fear coming from him and it was delicious the sight of him squirming just made it better as he roughly but slowly started to yank the tooth out he could hear the bone cracking as he pulled harder and harder on the tooth. Sans eye sockets widen his eyes started to glow he started to scream in pain or the best he could with Gaster’s hand basically in his mouth to touch the blood that is coming from his action. The younger skeleton could taste a rusty metallic taste as blood started to go down his mouth the pain wasn't like any he's ever felt before.

Tears were sliding down his cheekbones and onto the table now mixing with the blood coming from the sides of his mouth it's stain the table with the other blood from humans. He wanted to stop crying it was weakness and his brother was watching and most of all he just wanted to pain to stop his once Gaster finished yanking the tooth out he looked at his work. A hole where the tooth once was was still bleeding but to his somewhat surprise it was perfect kind of like pulling another monsters tooth he shoves his thumb into his mouth his black gloves were getting bloody he still had the same look only his smirk was wider. He looked at the tooth in his hand he was really pleased with this he put the tooth down.

  
The doctor looked over at Papyrus with a bit of surprise showing on his face Papyrus was shaking his eyes were glowing and he looked angry. Well, more that he was looking at Gaster with pure rage and hate he’s never felt like this before it was a confusing feeling. How could this to Sans his brother did nothing and he could feel another feeling he just didn't understand it was anger but for a different reason.

Even after all his brother has done to him he’s never felt like this like he wanted to see the older monster on the ground bleeding and Begging Papyrus to spare him. He let out a growl when the taller Skeleton got near him summoning a bone like Sans taught him he lunged at him ready to strike him down the bone at the end was sharp and in a spiral shape.

Gaster blocked him and continued as Papyrus was swinging at him this new development was interesting, to say the least maybe he wasn’t completely useless. The older Skeleton vanished and reappeared behind him twisting his arm the younger monster glared at him ignoring the pain that was being inflicted upon him.

“ ** _You may be useful than I once thought I’ll have to write this down_**.” He let go and walked out of the room leaving the two brothers alone in the room to go update his records on the two brothers. Papyrus went to Sans he ripped off the restraints it surprised Sans because before this his younger brother didn’t show much strength he sat up slowly with the younger monsters help he felt a rag on his face cleaning the blood. He checked his own soul his Hp didn't go down he suspects it had to do with the wires that Gaster put on him he took them off his HP went down a few decimals but was stable he looked at Papyrus.

Sans had no idea where Papyrus got the rag but he was being cleaned up by his younger brother he spits some blood out of his mouth as Papyrus was healing him. He’s always been better at healing than Sans was and he didn’t complain he looked at his tooth that was in a dish by the set of pliers. “ **HE HAD NO RIGHT TO DO THAT**.’’ Sans looked at his brother who hasn’t talked to him since the lesson he gave Papyrus.

“ **What do you mean? And it doesn’t really matter Pap I'm fine**.” He said he could tell that the other finished healing him but he didn’t have a new tooth which was interesting and he’ll have to do some experiment on that not on himself of course but he’ll get on that later.

Papyrus grabbed Sans by the face and glared at him with some worry in his eyes. “ **NO, IT’S NOT HE SHOULDN’T TOUCH YOU LIKE THAT SANS! HE SHOULDN’T TOUCH THINGS THAT ARE NOT HIS**!” Sans was confused at the way Papyrus said that he hit his hand away Sans got off the tab and put back on his shirt and coat he was glad there wasn't any blood on it since cleaning blood stains was a pain.

“ **It doesn’t matter like I said I’m fine Pap’s let’s go eat before Gaster decides to rip out one of your teeth**.” He mutters and walks out but he could tell that Papyrus was following him he conjures his tongue and licked where his missing tooth was he’ll have to replace it he thinks to himself just another day in the underground he sighs.


End file.
